1. Field of the Invention
This invention relates to a recording and/or reproducing apparatus which permits random access to recording tracks and is arranged to enhance the scanning head's efficiency.
2. Description of the Prior Art
Heretofore, developers have contrived various random access type recording and/or reproducing apparatus using recording media such as magnetic discs. In apparatus of this kind, information is often recorded on each track separately from information recorded on other tracks and is often erased independently of information recorded in other tracks. Therefore, when the apparatus is loaded with a disc that has undergone random erasing or a disc that has been only partially recorded, and one wishes to record on such a disc, an unrecorded track must be quickly located to rapidly shift the head to a position corresponding to the unrecorded track. In a conventional arrangement, the head is automatically shifted to the next recording track upon completion of recording on one track. If the next track is found already recorded on, the head is further shifted to another track until a vacant track is found. In such a conventional system, the head moves from one recording track to another while detecting the presence or absence of a recorded signal. Accordingly, the length of time required for accessing the vacant track increases with the number of tracks that must be skipped. Where it is only the last recording track that is found unrecorded and vacant, or where the recording medium has no vacant track, much time is wasted in a useless search and shift operation.
Another shortcoming of the conventional arrangement becomes evident when recording a signal requiring five or six tracks, for example, and only four consecutively vacant tracks remain. Recording would then have to be stopped unfinished and a valuable recording opportunity would be missed. Other arrangements have been contrived. In one, a track is provided in part of a recording disc especially set aside for recording a controlled signal. Information on the presence or absence of a record for a every recording track is recorded on the special, so that vacant tracks can be detected by reproducing the information recorded on the special. However, this system requires use of an additional recording reproducing head for the special track. This head must be shifted to a position corresponding to the special track each time a signal is recorded or erased from each of the recording tracks. Using such a method thus inevitably results in a complex structural and control arrangement.
The prior art thus has not been satisfactory with respect to a vacant track detecting or searching arrangement.